Why Is the Manchineel Tree Dangerous?

The manchineel tree is dangerous because its sap and fruit contain poison. Its other name is Hippomane, which comes from the Greek and means “causing horses to run mad”. The tree is a member of the Euphorbiaceae family and grows in topical America, producing a crop of acrid, bitter apple-like fruits which drop spontaneously and carpet the ground beneath it, earning manchineel the name manzanita de la muerte, or “little apple of death,” from Spanish conquistadors.

Resembling a small green crabapple about 1 to 2 inches wide, the sweet-smelling fruits can cause hours of agony — and potentially death — with a single bite.

The sap is white and highly caustic, so that a drop on the skin produces a burning sensation and raises a blister. It used to be believed by many that to sleep beneath the tree meant certain death. But the great 18th Century naturalist Nicolas von Jacquin “reposed under it for hours at a time without inconvenience”.

Manchineels are notorious in their native habitats, the sandy soils and mangroves of South Florida, the Caribbean, Central America and northern South America. Normally a hefty shrub, it can grow up to 50 feet tall, producing toxic timber that has long tempted Caribbean carpenters. And despite the danger, people have used manchineel to make furniture as it is beautifully patterned in brown and white, carefully cutting the wood and then drying it in the sun to neutralize its poisonous sap.

Before felling the tree by hand, workmen light a fire round the trunk, so that the sap thickens and does not run down the handles of their axes. Burning or chopping the wood isn’t advised, either, since its smoke and sawdust burn skin, eyes and lungs. Native people even used manchineel as medicine: A gum made from the bark can reportedly treat edema, while dried fruits have been used as a diuretic.

The most famous victim of manchineel is probably conquistador Juan Ponce de Leon, who led the first European expedition into Florida in 1513. He returned to colonize the peninsula eight years later, but his invasion met resistance from Calusa fighters. Some native Caribbean people used manchineel sap to make poison arrows, and one of these sap-tipped arrows reportedly struck Ponce de Leon’s thigh during the 1521 battle. He fled with his troops to Cuba, where he died of his wounds.

Although manchineel sap is poisonous to birds and many other animals, there are some creatures it doesn’t seem to bother. The garrobo or striped iguana of Central and South America, for example, is known to eat manchineel fruit and sometimes even lives among the tree’s limbs, according to IFAS.

Plant toxins typically evolve for defense, but it’s not clear why manchineel went to such extremes. Coastal living might have enabled it, since its seeds can travel by sea — sometimes across the Gulf of Mexico — rather than relying on animals. Regardless, toxicity became a liability for manchineels in Florida, where eradication efforts and habitat loss pushed it onto the endangered species list.

Yet while it’s less famous than toxic plants like poison ivy or hemlock, manchineel at least has relative notoriety among endangered plants, most of which are publicly unknown. And local respect for its risks, as well as benefits, may give it an edge over endangered plants with less star power and firepower.

People tend to leave manchineel alone, both for obvious reasons and because even this poison-obsessed tree provides ecosystem services. It’s a natural windbreak and fights beach erosion, for instance, a useful service in the face of rising sea levels and bigger Atlantic storms. And since biotoxins can inspire beneficial scientific breakthroughs like safer pesticides from scorpion venom or pain medicine from cone snails, it’s probably worth keeping manchineel around — at a safe distance.

Content for this question contributed by Albert Apuzzo, resident of Roselle, DuPage County and Cook counties, northeastern Illinois, USA